IV. 6. Coordinator's Report: Chromosome 5.
Jens Jensen, Agricultural Research Department, Risø National Laboratory, DK-4000 Roskilde, Denmark.
Recombinations between different Ml-a genes were investigated by Giese et al. (1980). Only four possible recombinants were found in a large material. From a chromosome-mapping point of view the genes studied, Ml-a, Ml-a3, Ml-a6, Ml-a9, Ml-a(Ar), and Ml-a(Ru1) may all be considered to be located in a single locus Ml-a. It was suggested that genes provisionally named Ml-a(Ar) and Ml-a(Rul) be called Ml-a12 or Reglt12 and Ml-a13 or Reglu13, respectively.
The high-lysine mutant Risø 56 is reported (Doll 1980) to be due to a mutation in or near the Hor2 locus on chromosome 5. It was suggested the gene be designated Hor2ca.
The dominant high-lysine gene Lys4d was studied in a four-point cross (Jensen 1981). The recombination percentages obtained was ert-b x nec1a 18.4 + 4.07, Lys4d x ert-b 30.3 + 5.13 Lys4d x necla 40.8 + 4.58, Lys4d x Ml-at 51.8 + 4.82, ert-b x Ml-at 47.6 + 5.91, and necla x Ml-at 42.0 + 4.66.
The linkage map in Figure 1 is prepared as usual by the map-estimation procedure described by Jensen and Jørgensen (1975). The two first recombination percentages mentioned above were utilized in addition to those used last year (BGN 10:88-90, 1980).
References:
Doll, H. 1980. A nearly non-functional mutant allele of the storage protein locus Hor2 in barley. Hereditas 93:217-222.
Giese, H., H. P. Jensen, and J. H. Jørgensen. 1980. Allelism of genes in the Ml-a locus. BGN 10:22-24.
Jensen, J. 1981. Location of the high-lysine locus Lys4d on barley chromosome 5. BGN 11:45-47.
Jensen, J. and J. H. Jørgensen. 1975. The barley chromosome 5 linkage map. I. Literature survey and map estimation procedure. Hereditas 80:5-16.
